The subject of the present invention is a device for control of an electric motor driving a moving object, for example a roller shutter or a door.
Such a device is known from the DE patent application 27 34 512. In this device, the switch controlling the power supply to the motor is open at rest, and it is closed by a centrifugal mechanism driven by the motor, the starting of the motor being undertaken by a delayed-drop-out start-up relay controlled by a manual push-button switch. The means of starting up the motor and the means of automatic stopping in the event of excess torque are thus combined, but in addition to its relative complexity, such a device requires special-purpose wiring for supplying the start-up relay.
A control device for a motorized roller shutter is also known from the patent EP 0 703 344, operating by detecting a sudden increase in the resisting torque exerted by the roller shutter on the motor. To this end, the chassis of the motor is mounted so that it can rotate and its rotation is limited by two springs acting in opposition and determining the excess torque to be reached in each direction of rotation for the rotation of the chassis to actuate a switch which cuts off the power supply to the motor. The reacting against the moving object may be caused either by its arrival at end-of-travel, or by an obstacle. Starting up the motor is carried out, in the conventional way, by means of a switch.
A device is provided for control of an electric motor driving a moving object, for example a roller shutter or a door, comprising a switch controlling the power supply to the motor and means for actuating this switch reacting to the moving object being restrained, particularly by an obstacle, so as to cause said switch to be opened and to cut off the power supply to the motor, these actuating means comprising a mechanical actuating device capable of taking up a first state in which the switch is closed and a second state in which the switch is open, and means for putting the mechanical actuating device into its first state, the actuating device being brought into its second state by the reacting against the moving object.
The object of the present invention is also to combine the means for automatic stopping of the motor with the manual control of the starting up of the motor, but via simple mechanical means requiring no auxiliary wiring and using a mechanical manual control, such as a rod control, with a cable or a cord.
The control device according to the invention is characterized by the fact that the mechanical actuating device is a bistable device and in that the means for putting the actuating device into its first state are exclusively manual.
The invention is applicable equally to a motor with one direction of rotation and to a motor with two directions of rotation.
The device requires no external wiring other than that necessary for supplying power to the motor. Installation is thereby simplified.
In its simplest execution, the actuating device is a rotating cam actuating a monostable switch and having, on its periphery, a notch with an angular width corresponding to the rotation of the cam which is necessary for actuating the switch and in which a spigot of the casing of the motor is engaged for driving it when the casing of the motor is driven in rotation, against the action of a spring, by the resisting torque.
According to another embodiment, the bistable mechanical device consists of a cylindrical part which is movable in translation and in rotation within a fixed cylindrical tubular part to which it is linked by the interaction of at least one stud guided by at least one ramp, this moving part being, on the one hand, pushed by a spring in the direction of the switch and, on the other hand, linked to a pulling element which can be actuated manually, making it possible to exert a pulling force opposite to the thrust of the spring, the device being brought into its second stable state either by the rotation of the casing of the motor against the action of a spring, this rotation of the casing being caused by the resisting torque created by said moving object being restrained, or by a further pulling force on the pulling element.